Nonlinear optical properties of CdTe included in sol-gel by a new technique

Abstract

Sol-gel derived silica glasses are well suited as host for molecular dopants that show specific optical properties, such as laser action (high second and third order nonlinear coefficients). Such materials are of interest in optical waveguide and switching for telecommunication networks. The material is prepared by sol-gel technique in which some nanocrystallites of semiconductor (II-VI) are included, specially CdTe. Nanocristallites are prepared out of the host matrix and included in the sol-gel after. The nanoparticles are prepared by sono-electrochemical technique. Sono-electrochemistry, or pulsed electrodeposition in presence of high intensity ultrasound, is used to produce powders. The nanoparticles are characterized by scanning and transmission microscopy, electron diffraction, and x-ray fluorescence. The nonlinear refractive index and absorption are measured by the Z-scan method at 532 nm (Nd-YAG pulsed laser).